<span>Ocean currents act much like a conveyer belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics. Thus, currents regulate global climate, helping to counteract the uneven distribution of solar radiation reaching Earth's surface.</span>
B: sediments melt deep beneath earth's surface
The earliest of civilizations were based around river valleys. This allowed them to irrigate fresh water to their crops allowing for better farming and therefore, bigger and better civilizations.
You didn't give your choices but sin 21 equals 0.358.
